I'm rusty with this. On sbs 2011 standard (using its exchange for mail), user a left and replaced with user b. User b should have everything like use a had it - old mail, contacts, calendar, desktop apps / shortcuts, etc.
New user b should get mail sent to user a.
I'm thinking this is the same if user a got married / changed name - firstname.lastname@example.org is now Janesmith@contoso.com and still gets Jane doe emails
What's the best way to deal with that?